The knee has many parts that can be damaged, there are many causes of knee pain. Learn about common injuries and conditions. Although it’s a fairly small part of the body, a lot can go wrong with your knee. Here’s an overview of just some of the conditions that commonly cause knee pain. Arthritis: One of the most common causes of knee pain that doctors see is arthritis, says Jonathan Shook, MD, an orthopedic surgeon in Indianapolis. There are several types of arthritis than can cause knee pain: Osteoarthritis causes the smooth, protective layers of cartilage in the knee to become worn, leading to damage in the bones in the knee. Rheumatoid arthritis affects the knee after the body’s immune system attacks a membrane within the joint, causing pain, inflammation, and damage […]